Im a Serbian citizen living in NYC and also im a green card holder. Can I travel to Cuba from nyc direct and do I need and visa?

For entry into Cuba, consult with the Cuban Embassy.

Can I go back to the states?

Depends on your particular circumstances and whether you obtained advance parole to return.

Can I comeback to US with GC application pending and a Visa in US finished

Likely not with a pending petition for permanent residency but this will be at the discretion of the port officer at time of entry.

EAD is pending for more then 175 days?

You can schedule an Infopass appointment at your local USCIS service center to inquire further. Service requests generally do not yield results.

What is the best possible option?

You can marry at any time and can petition for her thereafter. May be better to wait until you are a citizen to apply for her.

How do I explain to the Visa officer at my next interview

With a previous visitor visa denial, it is best to work with an attorney for a subsequent application as you were not able to provide enough...

Should I appeal my N-400 denial?

For questions about case strategy and making a determination about appeal, an attorney should review your entire file. Providing an answer on a...

It depends on the consulate and processing varies based on the location. Generally you should receive an interview date within 3-4 months of...

Without viewing the request it is very difficult to say. Generally court records refer to a criminal action on a state level.

Can i apply for the 2nd green card without getting my first?

No this is not a possibility under current immigration law.